As good a theory as that is, it has to be someone that Kakashi has seen.
Tobi said something along the lines of "You don't remember faces" last chapter.
Not Obito tho.
You seem like a kid yourself, I mean what kind of adult comes up with Shadow1DarkRasengun as a 'clever' name?
Not to mention the way you chose to type, makes you seem much younger than you 'are'.